The present invention relates generally to new and novel apparatuses for harvesting sod. More particularly, the present invention relates to automated sod harvesting apparatuses which automatically transport and position rolls of sod in a preselected pattern onto pallets.
Sod is becoming an increasingly popular means of ground cover, both for residential and for commercial purposes. There are many instances when a lush field of grass serves as the perfect ground cover. To achieve such a lawn, many people believe that planting grass seed is the most effective and efficient means. However, there are a number of problems which can prevent grass seed from growing into a full field of grass. One such problem is, of course, the weather. Different grass seed varieties require different weather conditions in which to thrive. Thus, one must know whether the grass seed being planted is adaptable to the surrounding weather patterns. Furthermore, the unpredictability of the weather makes planting grass seed guesswork at best. Grass requires a certain amount of water and sunlight to take root and grow. Once the seed is planted, one is at the mercy of nature to provide the requisite amounts of water and sunlight.
In addition, certain species of grass seed are more adaptable to the climate in different geographic regions. It is not always possible to know if the grass seed obtained corresponds to the climate it is to be planted in. Whether or not a particular species of grass will readily grow in its environment is largely a function of geography. Some grass species thrive in cool, wet climates while others grow best in hot, arid climates. Cool season grasses are grown generally in the northern states and in Canada. These grasses generally grow best during the cool spring and fall seasons, and less during the hot, dry summers. Once harvested as sod, these grasses can easily be formed into rolls and then transported to their place of laying. Kentucky bluegrass is a common, widely-used cool season grass. Warm season grasses are common in Florida and throughout the south. These grasses thrive in the hot climate. However, when these varieties of grass are out into strips of sod, they cannot, as a general rule, be formed into rolls. Bermuda grass is a typical warm season species.
Another drawback of planting grass seed is that the seeds require time to grow into a full, lush lawn. In fact, it may take many seasons before the lawn is completely full and thriving. This is important in two respects. First, of course, one cannot enjoy a beautiful green lawn as soon as the seeds are planted. Owners of both residential homes and commercial complexes are anxious to enjoy a green field of grass. If grass seed is planted, it may take months or even years for the lawn to be healthy and full. Second, and perhaps more important, while grass seed is growing, the underlying soil is not protected from the erosive effects of wind and water. This is especially true when grass seed is planted on rolling, sloping terrain. New grass is often needed after the completion of large-scale construction, as in the repair or construction of a stretch of road or highway. Grass seed is often planted in the earth adjacent to the road as it slopes down into a median or to the countryside. While this grass is beginning its growth, the underlying earth is subject to erosion.
All of these problems are contributing factors to the increasing popularity of the use of sod. Grass seeds are chosen and planted, and nurtured into maturity on sod farms. When the grass is green and lush, the sod is harvested. Harvesting machines cut the sod into strips and, depending on the species of grass being harvested, curl the strips into rolls. The rolls are then lifted and stacked onto pallets by sod workers. The sod rolls can then be transported, unrolled and placed end to end and side by side at the desired location. As the grass roots are already strong and mature, the grass will usually thrive in its new environment. The roots soon grow between the strips of sod and the lawn quickly becomes full and complete. Since the sod is already a full and complete ground cover, it prevents erosion of the underlying soil.
Several devices have been utilized to harvest sod; that is, cut the sod at a predetermined depth into strips and lift it from the ground. Once the sod is cut, it is often beneficial to form the sod into rolls. This facilitates the handling and transportation of the sod to its new location. Several devices have been utilized to curl strips of sod into rolls. Examples of such devices are shown in U.S. Pat. No. 3,164,211 to Scott, and U.S. Pat. No. 4,944,352 to Brouwer, et al. Often, the device used to form sod rolls is integrated into the sod cutting machine.
Once the sod is cut and formed into rolls, the rolls are then prepared for transportation. As noted earlier, many warm season grass varieties cannot be rolled. Once cut into strips, these varieties are simply stacked onto a pallet and then shipped to their destination. Most cool season grass species can be rolled without damaging the grass. Forming the sod strips into rolls makes it easier to handle the sod, and easier to stack onto a pallet. While there is no single industry custom, many farmers will stack sod rolls into a pallet in a cross-hatch configuration. Using this cross-hatch design, several layers of sod may be loaded onto a single pallet.
One current industry practice is to place ten rolls of sod per layer onto a square pallet. Four rolls of sod are placed side by side on two opposite ends of the pallet. Two rolls laying end to end are placed in between the two rows of four, transverse to them. The next layer is positioned in a similar fashion, except that, viewed from above, the orientation is rotated 90.degree.. This is repeated two more times until there are four layers of ten rolls. The fifth layer utilizes six rolls of sod. These six rolls of sod rest in the six gaps between sod rolls produced by the two rows of four rolls. The sixth and final layer contains four rolls which rest in the gaps of the six-roll layer. Thus, the fully loaded pallet is generally cubical in configuration, with a tapered top portion.
Another current industry practice is to place twelve or fifteen rolls of sod per layer onto a rectangular pallet. In such an arrangement, three sod rolls are placed end to end across the width of the pallet at one end. Depending upon the length of the pallet, and the size of the sod rolls, additional sod rolls are placed side by side to form three rows, each row containing either four of five rolls of sod. The next layer is positioned in a similar fashion except that, when viewed from above, the orientation is rotated 90.degree., thus forming four or five rows of three rolls of sod each across the width of the pallet. A third layer is added, the configuration of which is identical to the first layer, and a fourth layer, identical to the second layer, is also added. The fifth layer utilizes nine or twelve rolls of sod respectively when the rows are four and five rolls of sod in length. These nine or twelve rolls of sod are placed in the gaps of the preceding layer. A sixth layer is then added which consists of six or eight rolls which are again placed in the gaps of the preceding layer
The previously mentioned devices cannot position the rolls of sod into a desired configuration on a pallet automatically. These devices require people manually lifting the rolled sod and placing the sod rolls in its proper position on the pallet to achieve a desired stacking arrangement. This results in additional labor costs, and reduces the consistency of stacking from layer to layer and pallet to pallet due to human error and fatigue.
Thus, an object of the present invention is the provision of automated sod harvesting apparatuses which can stack sod rolls onto pallets into layers of preselected orientation.
Another object of the present invention is to provide automated sod harvesting apparatuses which can stack sod rolls into multiple layers onto a single pallet.
Still another object of the present invention is to provide automated sod harvesting apparatuses which do not require human assistance in arranging the sod rolls onto the pallets.
A still further object of the present invention is to provide automated sod harvesting apparatuses which can be adapted to fit existing sod harvesting machines.
Yet another object of the present invention is to provide automated sod harvesting apparatuses which are computer controlled.
Yet still another object of the present invention is to provide automated sod harvesting apparatuses which operate effectively and efficiently at differing tractor speeds.
These and other objects of the present invention are attained by the provision of an automated sod harvesting apparatus having a frame and a plurality of orthogonal axes therein. A conveyer apparatus is positioned on the x-axis and serves to transport the rolls of sod to a mechanical hand unit fixed to the conveyor assembly. The mechanical hand unit lifts the rolls of sod from the x-axis conveyor onto a pallet. The x-axis mechanism allows the entire conveyor to move along the path of a line parallel to the motion of the conveyor belt. A z-axis supports the pallet onto which the rolls of sod are positioned. The z-axis permits movement in a generally vertical direction, transverse to the movement of the x-axis. The z-axis comprises a plurality of forks mounted onto a hydraulic lift. When a pallet is fully loaded with sod rolls, the forks on the z-axis drop to the ground and the tractor drives away from the fully loaded pallet.
The hydraulic lift portion of the z-axis is attached to a y-axis. The y-axis permits movement of the z-axis, and thus of the pallet thereon, in a direction transverse to both the movement of the x-axis and the z-axis. Thus, by manipulating the y-axis and the z-axis, the pallet attached to the z-axis forks can be positioned at any point in the y-z plane. This collection of points defines a plane transverse to the x-axis. After a layer of sod rolls has been stacked onto the pallet, the z-axis lowers the pallet to allow the second layer to be stacked. This process continues until the pallet is full. A pallet injection unit which rides with the y-axis injects empty pallets into the z-axis. A pallet magazine, which can store several pallets at a time, supplies pallets for the pallet injection unit.
Other objects, advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.